New microarrays allow measurements to be made of 38,000 or more gene expressions on a single sample. We have recently used an Affymetrix array to examine up and down regulation of vaginal genes from a healthy premenopausal woman before and after administration of a probiotic. Somewhat to our surprise, we noted that over 9,000 genes were expressed and major down regulation occurred in cancer and other genes such as inflammatory cytokines. This was especially interesting as it showed that vaginal treatment could influence genes associated with, for example, the intestine. The array provided data or relevance to estrogen replacement therapy, namely the ability to detect and examine changes in estrogen associated factors.